Hi, in the spirit of PR 60324 and 61035, here's a patch that gets rid of the remaining potentially unbounded stack allocations in libgfortran. All uses of __builtin_alloca() and VLA's are replaced either straight with heap allocated memory, or with a fixed size stack buffer, potentially switching to heap storage for large sizes in places where performance might matter. In order to avoid reintroducing these kinds of issues, I also added -Werror=vla to AM_CFLAGS.
This might also help limited targets like nvptx that lack VLA's.
Regtested on x86_64-unknown-linux-gnu, Ok for trunk?
2014-11-13 Janne Blomqvist <j...@gcc.gnu.org>
PR libfortran/60324
* configure: Regenerated.
* configure.ac (AM_CFLAGS): Add Werror=vla.
* libgfortran.h (gfc_alloca): Remove macro.
(fc_strdup_notrim): New prototype.
* intrinsics/access.c (access_func): Use fc_strdup rather than
stack allocation.
* intrinsics/chdir.c (chdir_i4_sub): Likewise.
(chdir_i8_sub): Likewise.
* intrinsics/chmod.c (chmod_internal): New function, move logic
here.
(chmod_func): Call chmod_internal.
* intrinsics/env.c (getenv): Use fc_strdup rather than stack
allocation.
(get_environment_variable_i4): Likewise.
* intrinsics/execute_command_line.c (execute_command_line):
Likewise.
* intrinsics/hostnm.c (hostnm_0): New function, use static buffer
rather than VLA.
(hostnm_i4_sub): Call hostnm_0.
(hostnm_i8_sub): Likewise.
(hostnm): Likewise.
* intrinsics/link.c (link_internal): New function, use fc_strdup
rather than stack allocation.
(link_i4_sub): Call link_internal.
(link_i8_sub): Likewise.
(link_i4): Likewise.
(link_i8): Likewise.
* intrinsics/perror.c (perror_sub): Use fc_strdup rather than
stack allocation.
* intrinsics/random.c (random_seed_i4): Use static buffer rather
than VLA, use _Static_assert to make sure it's big enough.
* intrinsics/rename.c (rename_internal): New function, use
fc_strdup rather than stack allocation.
(rename_i4_sub): Call rename_internal.
(rename_i8_sub): Likewise.
(rename_i4): Likewise.
(rename_i8): Likewise.
* intrinsics/stat.c (stat_i4_sub_0): Use fc_strdup rather than
stack allocation.
(stat_i8_sub_0): Likewise.
* intrinsics/symlink.c (symlnk_internal): New function, use
fc_strdup rather than stack allocation.
(symlnk_i4_sub): Call symlnk_internal.
(symlnk_i8_sub): Likewise.
(symlnk_i4): Likewise.
(symlnk_i8): Likewise.
* intrinsics/system.c (system_sub): Use fc_strdup rather than
stack allocation.
* intrinsics/unlink.c (unlink_i4_sub): Likewise.
* io/file_pos.c (READ_CHUNK): Make it a macro rather than variable.
* io/list_read.c (nml_get_obj_data): Use fixed stack buffer, fall
back to xmalloc/free for large sizes.
* io/read.c (read_f): Likewise.
* io/transfer.c (MAX_READ): Make it a macro rather than variable.
(WRITE_CHUNK): Likewise.
* io/write_float.def (write_float): Use fixed stack buffer, fall
back to xmalloc/free for large sizes.
* runtime/string.c (fc_strdup_notrim): New function.
--
Janne Blomqvist
vla.diff.gz
Description: GNU Zip compressed data
